weiss



Aug. 16, 1932 UNITED, STATES CARL W. WEISS, OI BROOKLYN, m YORK PATENTOFFICE :onrr

ol'lhlll I0. 1,700,703, dated July 1, 1m, Serial lo am m 1, ma.

ble of relative angular displacement have co-acting portions withroximate faces formed with non-concentric grooves with theirlongitudinal axes intersecting at an angle and a relatively movable bodyreceived 10 partly in each of such grooves and throughwhich force istransmitted from one coactin portion to the other, such relativelymovable body. lying always in a plane whlch bisects the angle ofdisplacement of the two members, whereby there is no relativefluctuation of angular velocity of the driven member as compared withthat of the driving member. Universal joints constructed as shown anddescribed in said patent, are :well adapted for use where the angle ofdisplacement does not much exceed 20, as in their application topropeller shafts in the conventional rear wheel drive of automobiles.When, however, the relative a ar d1splacement of the two members 0 theuniversal joint is much larger than 20, as in the application ofuniversal joints to the front. wheel drive of automobiles, and provisionfor angular displacement of 35 or 40 must be made, regard must be had toconsiderations which are not obvious when the angle of displacement isrelatively small. Thus, not only must the unit which embodies theuniversal joint be small in diameter so as to permit, for example, theplacing of the steering knuckles and brake drum within the establishedwheel radius of the conventional rear wheel drive, but it must have amuch greater torque capacity. The torque 40 capacity of the conventionalpropeller shaft unit must be equal to the engine torque multiplied bythe transmission gear reduction,

or four times the engine torque if the ratio of the low geartransmission is 4:1. When a such unit is placed directly in the wheel,for

. 881,114, fled July 26, 1988. Applicatioril'orreluu Serial Io. 880,581.

front wheel drive, its torque capacit must be equal to the engine torquemultip 'ed by the transmission gear reduction and a ain multiplied bythe difl'erential ratio an is expressed by the formula TX4X4 2 Eintapplied to t e rear drive propeller shaft.

cause of the limitation of space the universal joint cannot be increasedin size in roportion to the increase in torque. At e same time,theincrease in space required, with the greater angular displacement,for the coaction of the projectin V they may be called or 'convenience,of the two members of the joint reduces the dedendum section of thetooth to such an'extent that, in such a construction as that illustratedin the patent above referredv to, the torque capacity of the joint wouldbe greatly reduced or twice the to He capacity of the universal portionsor teeth, as

and, 1n such location, the joint would not be capable of transmittingthe required torque. It is, therefore, the ob ect of the presentinvention to modify the construction of the joint shown in said patentin such manner that each such projecting portion or tooth of each membershall be reinforced suficiently to compensate for the reduced dedendumsection required by the greater angular displacement of the joint. Inaccordance with the invention each tooth is so formed, either in cuttingor by the welding on of a reinforcement, that the tooth is strengthenedto the degree necessary to give it the re uired tor we capacitynotwithstanding the re uction of t ededendum section necessary to permitthe greater angular displacement. In accordance with the invention eachprojecting portion or tooth is extended beyond the reduced contactportion of its dedendum to form a reinforcement sufiicient to compensatefor the reduction of the dedendum section."

The invention will be more fully explained hereinafter with reference tothe accompan ing drawing in which it is illustrated and in which:

Figure; 1 is a view in longitudinal section through a universal jointwhich embodies the invention, the intermediate, relatively movablebodies, the central, spherical supportin member and the shafts, whichare broken 0 to save space, being shown in elevation,

Figure 2 is a view in transverse sectional elevation of the joint shownin Figure 1.

Figure 3 is a view in longitudinal, sectional elevation of one of themembers of the j omt. F' 4 is a view in and elevation of the mem r shownin Figure 3 the sition of the cutter by which the teeth of e member areformed being also indicated.

Figure 5 is a view generally similar to F ig-. ure 3 but illustratingthe position of the millcutter in one of the grooves. i" 6 shows a viewin elevation of one of the teeth and a view of the same in 'section.

In the embodiment of the invention illustrated in'the drawing thedriving member a' of the joint is formed with three projectin rtions orteeth a with radial faces an esigned to coact with correspondingrojectmg rtions or teeth 6 of the driven member The members a and b areshown as formed integral with the shaft portions 0' and b, respectiveland the two members are shown as cente upon a spherical bearing d; Inthe proximate face of each proecting portion a, b, of the two members a,there is formed a oovec. The two grooves of the two proximate faces ofcoactmg portions of teeth of the joint members are ormed as describedin'said patent, so that their longitudinal axes, whether straight orcurved, are non-concentric or are oppositely dis with respect to eachother so that they mtersect, in all positions of angular displacement ofthe J'loint, in a plane which bisects the angle of 'splacement of thetwo members. Force is transmitted from one contact of the proximatefaces of the coacting portions, or teeth of the two members, but throughan intermediate and relatively movable body which is shown as a rolleror ball f. The two members of the joint may be retained in operativerelation by partly spherical, flanged shells g and g and bolts h. All ofthe parts thus far ,referred to may be arran (1 and operate in the samemanner as in t e universal joint shown and described in said patent andtheir arrangement and operation need not be further described herein.

The present invention is concerned with the formation of the proximatefaces of the coacting ro'ections or teeth of the two mem bers of t ejoint so as to provide the space necessary to permit the relativelyangular displacement of the two members through a relatively largeangle, such as 30 or 40, for example, and at the same time compensatefor the reduction of the dedendum section of each tooth incident to theprovision of such space. To enable the formation of the tooth to beunderstood more readily it will be best to describe firstone way, inwhich the tooth is formed as to its proximate faces, it being understoodthat each tooth is first formed by any suitable means substantially asshown in said patent, the three teeth being distributed at equaldistances and spaced apart by equal spaces.

When the member has been thus formed it is placed in a milling machineand a truncated milling cutter k, such as that represented by brokenlines in Figure 4, is introduced between the fiat, proximate faces oftwo successive teeth, the cutter being introduced to such a distancethat its outer or rearward face In, adjacent to its stem It, is movedwithin the outer riphery of the joint member to a substantial distance,as indicated in Figure 4. Then the joint member is oscillated about itsaxis a, indicated in Figure 4, so that the cutter 'cuts into the lateralfaces of the teeth of the joint member and is also oscillated upon theaxis at, indicated in Figure 3, so that the proximate faces of the teethof the joint member are cutout in-an axial direction with respect to thejoint member. It will be understood that the joint member may beoscillated in either one or both of the directions referred to while themilling cutter rotates on a fixed axis, or that the milling cutter mayitself be oscillated with respect to the joint member so as to cut outthe material of the proximate faces of the two teeth.

It will be seen that the effect of this milling operation is'to cut awayor reduce or relieve the dedendum of each tooth, as indicated by thebroken lines at a. in Figure 6, and at the same time to leave areinforcement, indicated at a, tapering from the bod of the joint memberto the pitch line member of the joint to the other, not through of t etooth, forming a substantial reinforcement for the tooth suflicient tocompensate for the reduced section of the dedendum. This reinforcementextends beyond or overlaps laterally the space between the dedenda 0 twoadjacent teeth. It will be obvious that this reinforcement might beformed by welding a reinforcing pieceto the other radially outside ofthe contact faces of the teeth, being an integral part of each toothwhether the tooth is formed by millin or by welding. After the proximatefaces 0% the teeth have been formed as described the grooves a may beformed therein as by a spherical or other suitabl formed milling;cutter, as indicated at l in igure 5.

It will be observed that the addendum a" of each tooth is cut awaysomewhat, as indicated at a in Figures 1, 3 and 5, in order that it mayenter the corresponding space between two teeth of the opposite memberwithin the line of the reinforcement.

I claim as my invention: I A universal oint having two members ca-Eableof relatively angular displacement and aving coacting teeth withtheir proximate faces formed with non-concentric ves intersecting at anangle and a relativ y mov- 10 able body received partly in each of suchgrooves and through which force is transmitted from one coacting rtionto the other, each proximate face 0 each tooth being relieved within itsouter surface to form 15 a space between two adjacent teeth for 00-action with the corresponding tooth of the other member, and to leave areinforcing portion at the outer surface of each tooth at each sideextending laterally over the space 90 between adjacent teeth.

' ification signed this 30th day This June, A. 1932.

' CARL W. WEISS.

